1. Field of the Invention
The field of the present invention is grounding systems for photovoltaic or solar arrays.
2. Background
As the demand for clean energy sources increases, manufacturers of photovoltaic arrays are driven to reduce costs. To meet demand, without sacrificing system quality and safety requirements, some manufacturers seek to improve installation efficiencies. Few manufacturers, however, have effectively improved installation efficiency related to grounding methods, while meeting or exceeding safety standards. This lack of effectiveness is likely due, in part, to the complexity of framing and mounting systems used for many types of photovoltaic arrays.
According to internationally accepted standards for photovoltaic arrays, grounding is required for each module of a solar panel. To ground each module, conventional systems use copper ground wire laid along each row in a module array. For larger scale installations, this may amount to the laying of several hundred feet of wire. The wire is then physically and electrically coupled to the frame of each module, using fasteners affixed to the outer surface of the module frame. Electrical coupling is typically achieved by connecting the wire to a lay-in lug, which is then coupled to a star washer, screw, and nut. The star washer, screw, and nut combination is used to penetrate anodized coatings disposed on the module frame.
When this type of grounding method is used, material and installation costs are substantial. Material costs include purchasing copper ground wire, typically heavy gage wire ranging from 6 to 8 American Wire Gage (AWG), as well as coupling hardware. Installation costs include, but are not limited to, costs for time and labor. Installers may, for example, be required to transport cable and hardware, lay cable, and fasten cable to each module in the array. Thus, installation is often time consuming and laborious. While this type of installation method is suitable for its intended purpose, more effective grounding systems for photovoltaic arrays are needed, particularly as demand for clean energy sources continues to increase.